The present invention relates to a line spacing mechanism for printing machines, in particular for typewriters.
In known mechanism, the line spacing movement of a platen roller is produced by a ratchet arrangement connected to a coupling actuated directly by the motor of the machine. The roller is held firmly at predetermined positions by suitable spring-detent positioning means. Such a construction is found to be expensive and does not permit easy movement in both directions of the platen roller or the possibility of positioning with micrometer accuracy.